Sulphited cation exchangers



STAES PATENT OFFICE SULPHITED CATION EXCHANGERS Eric Leighton Holmes, London, England, asslgnor to The Permutit Company, New York, N. Y., a corporation of Delaware No Drawing. Application September 5, 1942,

UNITED 'Serial No. 457,520. In Great Britain September 10. 1941 13 Claims. (Cl. 252-193) This invention relates to improved cation exchangers, the preparation thereof and the treatment of liquids therewith.

A number of organic cation exchange materials parent from the following description of my invention.

I have found that these sulphated or sulphonated organic cation exchangers or exchange reshave been developed fairly recently which have ins prepared by sulphiting during their formanumerous advantages over the older types of mintion can be given substantially higher capacities eral zeolites made from glauconite and other silifor performing cation exchange reactions withceous minerals. Since these new exchange maout injuring their other properties, by a treatterlals are non-siliceous, there is no danger of nLent of such materieilshwitlii 1a solution 1of a solimparting silica to a liquid being treated. Also, 1 18 c mp d of su p ur oxide. Su P r us they can be regenerated successfully with acids acid or the various sulphitcs are Satisfactory for as well as with solutions of salts. his purpose, including the common sulphites One class of such organic cation exchange me... such s alkali sillphites. e alkali bisulphites, terials is the group prepared by treatment of an and other compounds such as NazSaOs which is organic carbonizable substance such as anthraknown s So pyrosulp te or sod u meta cite coal, bituminous or semi-bituminous coal, p tc. lignite, products derived from the waste liquors The cation exchanger treated may have been of the sulphite cellulose process, sludges or other culphated or sulphonated just p r t s ph tresiduless derived from thiet purification of petrole- 2 5 :5 1 x321 551 5 22 izf g rg rg ag igl um oi and asphalts w h strong sulphating or e sulphonating agents such as concentrated sulfi s gi f gz g i gz g fi i g gs figggg a g phuric acid, fuming sulphuric acid, chlorosulphonic acid, sulphur trioxide gas or the like. g g g g may s 2 5 g g The reaction taking place in thepreparatlon of i? a 0mm on as u i 5 these products probably involves oxidation as well 25 g g ggg ggi gg g gfi 3 23: d 3%;? as sulphation or sulphonation.

Another class of such organic cation exchangga gg ifii b 3: fiz g g' g gg ers is the synthetic resin products. A number of ggz g treatment g phygcal such resins have been produced heretofore which have cation exchanging properties, including resgg gg f fis ga fi bgg f i g gfigggfiggg gfig ins prepared by condensation of an aldehyde with phmng treatment a tannin: a natural a synthetic The sulphiting treatment of this invention propolyhydnc phenol These and other Such resins duces a substantial increase in the cation exi i g then z with a change capacity of these materials, regardless of ng fi {ng g m s 1' whether they are regenerated with an acid or a e y i no 5 een salt when used for carrying out the cation exp ed pFeVmuS 0 con ,ensa on an a change reactions. A product which contains hyhyde.1Var1o1l11s other resins are known for use dmxyl groups in addition to 803}; groups, Such as j on angelis m which $03K gfwps are 40 as is obtained by an oxidizing sulphation or sulq m the by treatmfent 5111' phonation of coal or other organic material, is phatmg 9 sulphonatmgf agent elthe? durmg the particularly advantageous for treatment accordpreparation of the resin, or after it has been mg to this invention formed. Still other cation exchange resins have The material treated with sulphumus acid or Prepared y l'eactlon of an aldehyde, $111- sulphite may be in any'suitable condition when phlte and a monohydroxybenzwa subjected to the treatment. It does not appear Q object of y invention s the provlswn of to make any substantial difference whether the io c e s of the foregoing t p having material treated contains exchangeable hydroan increased capacity for cation exchange reacgen or an exchangeable cation such as sodium, tions. magnesium or calcium. It is more convenient,

A further object resides in the improvement of however, to have only one kind of cation present organic cation exchangers that contain SOsH during the sulphiting. groulpsJ 1by a treatment of such gaxcilangers with Ordinarily, theiz treatnlientmwltlii thi sulphiting a so u e compound 0 su p ur d ox e. reagen s advan ageous y c 6 cu a an ele- Other objects will be explained or will be apvated temperature of the order of to 200 C.,

and it is desirable, although not essential, to carry out the reaction under pressure as in an autoclave or similar apparatus. For most purposes, a reaction temperature of 110 to 130 C. is particularly satisfactory.

The sulphated or sulphonated cation exchange material may be simply mixed with a moderately strong aqueous solution of the sulphiting reagent and heated for a period of time at the desired temperature, either under a reflux condenser or in a suitable pressure vessel. At the end of the reaction period, the exchange product is washed with water, regenerated with a dilute solution of acid or a suitable salt solution and is then ready for immediate use as a high capacity cation exchange product.

Other reagents such as aldehydes may be present during the sulphiting reaction, although under most conditions, I have found that somewhat better increases in ion exchange capacity are obtained if an aldehyde is not used.

The invention is further illustrated by the following specific examples, although it is to be understood that the invention is not limited to the particular procedures or details of these examples.

Example I.200 parts by weight of bituminous coal were sulphated or sulphonated with 600 parts of 20% fuming sulphuric acid, then washed, neutralized with dilute sodium carbonate solution and dried.

A measured portion of this product was placed in a tube and measured quantities of hard water passed through it until hardness appeared in the efiluent. The exchange product was then regenerated with sodium chloride solution and the procedure repeated for a number of cycles. The product was then similarly tested for exchange capacity using a dilute solution of sulphuric acid as the regenerant. Results of these tests are shown in the table below.

The sulphated or sulphonated coal product in a sodium exchanging condition was then heated under a pressure of about 2.7 atmospheres at a temperature of 130 C. for three hours with about twice its weight of a 30% aqueous solution of sodium pyrosulphite (NazSzOs) The sulphited product was then washed and tested for exchange capacity in both the sodium and hydrogen cycles. The exchange capacities of the products before and after the sulphiting treatment are shown in Table I.

Example II .60 parts of bituminous coal were sulphated or sulphonated with 180 parts of 20% fuming sulphuric acid and the product was tested as in Example I. This product was then heated under a reflux condenser at a temperature of 108-110 C. for three hours with about three times its weight of a 33% aqueous solution of sodium sulphite (NazSOs). After washing this product was again tested for exchange capacity, the capacities before and after the sulphiting treatment being shown in Table I.

Example III.A cation exchange resin was prepared by mixing 300 m1. of 40% formaldehyde solution with a solution of 200 g. of quebracho tannin in one liter of water, and 20 g. of NaOI-l as a catalyst. This mixture was heated on a water bath for one hour until it set to a gel, and the gel was then broken up and dried at 80-90 C. The dried particles were ground to 20-30 mesh and sulphated or sulphonated with 20% fuming sulphuric acid using two parts of acid by weight to one part of the resin. The sulphated or sulphonated resin after washing and neutralizing In the following table, the exchange capacity test data for each of the foregoing examples are summarized with the individual capacities set forth in terms of milliequivalents per gram (meq./g.) and milliequivalents per liter (meq./l.) of exchange material when regenerated with sodium chloride solution (sodium cycle) and when regenerated with dilute sulphuric acid (hydrogen cycle). The density, given in terms of grams per liter (g./l.), is expressed on the dry (105 C.) basis, and was determined by backwashing and draining a bed of granular material of known weight in a calibrated tube.

The terms and expressions which I have employed are used as terms of description and not of limitation, and I have no intention, in the use of such terms and expressions, of excluding any equivalents of the features shown and described or portions thereof, but recognize that various modifications are possible within the scope of the invention claimed.

I claim:

1. A process of increasing the ion exchange capacity of cation exchangers comprising treating an organic cation exchanger containing sulphonic groups with a water soluble compound of sulphur dioxide at a temperature of about 100-200 C.

2. A process of increasing the ion exchange capacity of cation exchangers comprising reacting a member of the group consisting of sulphated organic cation exchangers and sulphonated organic cation exchangers with a solution of a compound of sulphur dioxide at a temperature between about 100 and about 200 C.

3. In a process of increasing the ion exchange capacity of cation exchangers, the step of reacting a cation exchanger comprising a member of the group consisting of sulphated and sulphonated members oi the coal family with an aqueous solution of a compound of sulphur dioxide at a temperature between about and about 200 C.

4. In a process ofincreasing the ion exchange capacity of cation exchangers, the step of reacting a cation exchanger comprising a member of the group consisting of sulphated bituminous coals and sulphonated bituminous coals with an aqueous solution of a soluble sulphite at a temperature of between about 100 and about 200 C.

5. In a process of increasing the ion exchange capacity of cation exchangers, the step of reacting a cation exchanger comprising a member of the group consisting of sulphated resins and sulphonated resins with an aqueous sulphite solution at a temperature between about 100 and about 200 C.

6. In a process of increasing the ion exchange capacity of cation exchangers, the step of reacting a cation exchange suiphitedresin with an aqueous sulphite solution at a temperature between about 100 and about 200 C.

7. An organic cation exchanger having a high capacity for exchange reactions prepared by treatment of a cation exchanger containing sulphonic groups with an aqueous solution of a sulphite at a temperature between about 100 and about 200 C.

8. An organic cation exchanger having a high capacity for exchange reactions prepared by treatment of a cation exchanger of the group consisting of sulphated carbonizable substances and sulphonated carbonizable substances with an aqueous solution of a sulphite at a temperature between about 100 and about 200 C.

9. An organic cation exchanger having a high capacity for exchange reactions prepared by treatment of a cation exchanger of the group consisting of sulphated and sulphonated members of the coal family with an aqueous solution oi. a compound of sulphur dioxide at a temperature between about 100 and about 200 C.

10. An organic cation exchanger having a high capacity for exchange reactions prepared by reaction of a member of the group consisting of sulphated coals and sulphonated coals with an aqueous solution of a sulphite at a temperature of between about 100 and about 200 C.

11. An organic cation exchanger having a high capacity for exchange reactions prepared by treatment of a member of the group consisting of sulphated cation exchange resins and sulphonated cation exchange resins with a solution of a compound of sulphur dioxide at a temperature between about 100 and about 200 C.

12. An organic cation exchanger having a high capacity for exchange reactions prepared by reaction of a cation exchange resin treated with a member of the group consisting of sulphating reagents and sulphonating reagents during its preparation with a solution of a compound of sulphur dioxide at a temperature between about and about 200 C.

.13. An organic cation exchanger having a high capacity for exchange reactions comprising a cation exchange resin prepared by treatment with a sulphite that has been reacted thereafter with a solution of a compound of sulphur dioxide at a temperature between about 100 and about 200 0.

ERIC LEIGH'I'ON HOLMES. 

